Add NES 6502 Assembly Support

[paulmcquad]

I would really like to help add support to Load NES Files for the 6502 instruction set.

[Dax89]

Both Loader and 6502 Assembler needs to be implemented.

I think capstone supports 6502 instruction set so it's fairly easy: there is a plugin called capstonebundle (https://github.com/REDasmOrg/REDasm-Assemblers/tree/master/capstonebundle) so it needs to be implemented there.

The loader part is pretty straightforward: only the NES file format documentation is needed in order to add segments, functions and entry points (loaders are in this repo: https://github.com/REDasmOrg/REDasm-Loaders)

If more informations are needed, let me know!

[paulmcquad]

Is this helpful to create a MOS65xx instruction set support? -> MOS65xx - Sebastian Macke sebastian@macke.de implemented it.

[Dax89]

Yep! capstonebundle plugin provides a ready to use capstone dependency, you can check the already done ARM implementation (MOS65xx should be even simpler than that).

The plugin also provides a thin wrapper above Capstone's API in order to simplifying some things.

[paulmcquad]

This is a start. I know next to nothing about plugins so i little help will go a long way. Thanks.

redasm-dev/processors#4

[paulmcquad]

Added MOS65xx Folder Plugin.

I'm trying to build the plugin. What is this the best way? I added "CS_ARCH_ALL" to the plugin.cpp: 27 + 28. ->
MOS65xx Folder (WIP) - Crashes Build

[Dax89]

You can add it in CMakeLists.txt: https://github.com/REDasmOrg/REDasm-Assemblers/blob/master/CMakeLists.txt

Capstone engine needs to be initialized too: capstonebundle plugin provides an easy way to do so, for example:

// capstone.h
#include "../capstone.h"

class MOS65XX: public Capstone {
  public:
    Capstone(RDContext* ctx); // There is also a "cs_mode" argument, I don't know if this architecture needs it
    void emulate(RDEmulateResult* result) override; // This implements the algorithm (jumps, calls etc)
    void render(const RDRendererParams* rp) override; // This renders instructions visually
};

// capstone.cpp
#include "mos65xx.h"

MOS65XX::MOS65XX(RDContext* ctx): Capstone(ctx, CS_ARCH_MOS65XX, 0) { }

void MOS65XX::emulate(RDEmulateResult* result)
{
    rd_address address = RDEmulateResult_GetAddress(result);
    auto* insn = this->decode(address, RDEmulateResult_GetView(result));
    // Instruction is decoded, you can use Capstone API to analyze it
}

void MOS65XX::render(const RDRendererParams* rp)
{
  // You can render instructions here
}

This class is the one you called MOS65XXLE/BE, I don't know too much about this architecture, but you can implement Little/BigEndian mode by just setting cs_mode argument (https://github.com/capstone-engine/capstone/blob/master/include/capstone/capstone.h#L124), after the decoding the emulation/rendering steps are the same).

For reference you can check:

• ARM32/64: Capstone Based: https://github.com/REDasmOrg/REDasm-Assemblers/blob/master/capstonebundle/plugin/arm/arm.cpp
• x86/x86_64, Pure REDasm API, useful to check emulation, rendering and lifting (this can be omitted, it's an advanced feature): https://github.com/REDasmOrg/REDasm-Assemblers/blob/master/x86/x86.cpp

NOTE: You don't need to import ../../capstonebundle/capstone/include/capstone/mos65xx.h directly, it's managed by capstone engine (see below).

I don't know if it's more clear now, but thanks for the new plugin btw!

[paulmcquad]

It's still not ready but i think if anyone can let me know what to do next? Thanks guys.

MOS65xx Plugin 2 - Arch Setup (WIP)

[paulmcquad]

I got the GUI and Basics setup but still no output. At least it builds now. I need to add the emulation/rendering part now. NE ideas how? ->
MOS65xx Plugin 4 - GUI Support (FIX Build)

[Dax89]

I have added some notes here redasm-dev/processors#4